Filters are employed in electronic equipment, such as computers, for filtering out radio frequency interference ("RFI") or electromagnetic interference ("EMI") thereby precluding spurious operation of the electronic equipment due to the external influences exerted by other mechanical or electrical equipment in the environment of the electronic equipment.
For example, the filter may comprise a cylindrical sleeve, such as an extruded tube of ferrite coated with barium titanate, as described and claimed in U.S. Pat. No. Re. 29,258 (assigned to the assignee of the present invention). The filter sleeve may be encapsulated in a filter assembly intended for use in printed circuit ("PC") boards, such as that described and claimed in U.S. Pat. No. 4,553,114 (also assigned to the assignee of the present invention). In this '114 patent, a through conductor or wire is slidably received within the bore of the filter sleeve, and the eyelet portion of a ground pin is received over the filter sleeve. Thereafter, the filter sleeve is soldered or otherwise suitably secured to the conductor and to the eyelet portion of the ground pin, respectively, for mechanical and electrical engagement therewith. The respective ends of the through conductor are bent downwardly at right angles thereto, substantially in parallel with the depending ground pin, so as to form three legs of the filter assembly. The eyelet of the ground pin, together with the filter sleeve and the respective adjacent portions of the through conductor, are thereafter encapsulated with a suitable insulating means.
While perfectly suitable for the purposes intended, nevertheless the filter assembly described and claimed in the aforesaid '114 patent does not readily lend itself to automated production, nor are the respective filter assemblies conveniently carried on a continuous strip.
Additionally, the filter sleeve in the '114 patent is disposed substantially at right angles to the ground pin and to the respective downwardly-bent outer legs of the filter assembly. With this arrangement, the length of the filter assembly is essentially controlled by the distance between the respective outer legs thereof, which constitutes the limiting dimension or factor, and thus further improvements in compactness are necessarily constrained due to the structural arrangement of the respective components of the overall filter assembly.